Power relay with low voltage control

ABSTRACT

A power relay, in a protective casing, is demountably attached to a low voltage relay control switch in a separate insulating casing adapted for attachment to the bottom side of a conventional outlet box, with the power relay solenoid projecting outside the box. A solenoid, operated by low voltage pulses directed through the low voltage relay control switch from a remote momentary switch and power source, progressively actuates a stepping rotary cam to alternately make and break the power relay in response to successive pulses, and a mechanical connection between the cam and the low voltage relay control switch through the bottom of the power relay casing, reverses the low voltage relay control switch each time the power relay is reversed.

United States Patent Primary Examiner-Har0ld Broome ArtorneyLynn l-l. Latta ABSTRACT: A power relay, in a protective casing, is demountably attached to a low voltage relay control switch in a separate insulating casing adapted for attachment to the bottom side of a conventional outlet box, with the power relay solenoid projecting outside the box. A solenoid, operated by low voltage pulses directed through the low voltage relay control switch from a remote momentary switch and power source, progressively actuates a stepping rotary cam to alternately make and break the power relay in response to successive pulses, and a mechanical connection between the cam and the low voltage relay control switch through the bottom of the power relay casing, reverses the low voltage relay control switch each time the power relay is reversed.

POWER RELAY WITH LOW VOLTAGE CONTROL BACKGROUND OF THE INVENTION Low voltage remote control relay systems utilizing stepping solenoids responsive to remotely transmitted pulses, are disclosed in my prior U.S. Pat. Nos. 2,547,999 and 3,428,924, and in Hutt U.S. Pat. No. 2,324,844.

DESCRIPTION The present invention has as its general object to provide such a remotely controlled relay system having improved versatility and applicability. A specific object is to provide such a relay having a remotely controlled power relay and also a low voltage relay control switch demountably coupled to the power relay and fully insulated therefrom, yet having its actuator mechanically connected thereto for conjoint operation.

Another object is to provide such a relay assembly which can readily be associated with a standard electrical outlet box.

These and other objects will become apparent in the following specifications and appended drawings, wherein:

FIG. I is a plan view of a relay assembly embodying the invention;

FIG. 2 is a longitudinal sectional view of the same, taken on line 2-2 of FIG. 1;

FIG. 3 is a transverse sectional view of the same, taken on line 3-3 of FIG. 2;

FIG. 4 is a transverse sectional view thereof, taken on line 4-4 of FIG. 2;

FIG. 5 is a top horizontal sectional viewof the same, taken on the line 5-5 ofFlG. 2;

FIG. 6 is a horizontal sectional view thereof on a lower plane, indicated by line 6-6 of FIG. 2;

FIG. 7 is a horizontal sectional view of the same, taken at a still lower level, as indicated by line 7--7 of FIG. 2;

FIG. 8 is a horizontal sectional view of the same, taken in a plane below the bottom of the main relay casing and showing the low voltage relay control switch case in plan, as indicated by lines 8-8 of FIG. 2;

FIG. 9 is an end elevational view showing the assembly lock;

FIG. 10 is a side elevational view of the assembly;

FIG. 11 is a longitudinal sectional view of a modified form of the low voltage relay control switch; and

FIG. 12 is a composite circuit diagram showing, in subcircuits, a plurality of the relay assemblies of the invention, in varying applications thereof.

Referring now to the drawings in detail and in particular to FIG. 2, I have shown therein, as an example of one form in which the invention may be embodied, a relay assembly comprising, in general, a power relay unit A having a solenoid type actuator B, and a low voltage relay control switch C demountably attached to unit A.

Relay unit A and actuator B together constitute an impulse relay which is in some respects the same as the relay disclosed in my prior US. Pat. No. 3,428,924, issued Feb. 28, I969. The relay unit A comprises generally a rectangular frame 15 ofinsulating material mounted within a sheet metal yoke 16 and retained therein by a cover plate 17. Frame 15 is open at top and bottom and H-shaped in cross section, consisting principally of sidewalls 20, end walls 21 and 22, a horizontal medial'web 23 having an opening 24 between its ends, and a bridge 25 integrally connecting sidewalls at the top, as in my prior US. Pat. No. 3,428,924. Yoke 16, in accordance with the present invention, comprises a bottom 28 closing the open bottom of frame 15, end arms 29 and 30 abutting the ends of frame 15 and having lateral retainer lips 31 embracing the four corners of the frame, and central lateral tabs 32 (FIG. 1) having respective bendable fingers 33 for securing the cover 17 down against the top of frame 15. At this level, the lips 31 are provided with notches 34 (FIG. 10) receiving notched corners of cover 17, which is of insulating sheet material of sufficient resiliency so that it can be bowed upwardly at the center to allow its corners to be sprung into the notches 34 during assembly of unit A. To secure the central area of cover 17, fingers 33, originally in the same plane as tabs 32, are bent inwardly, their lower edges disposed substantially in the plane of the upper surface of cover 17 so as to engage the cover in retaining relation. Tabs 32 are received in shallow slots 35 in the sides of frame 15 and in notches 36 in the sides of cover 17.

Tabs 32 and retainer arms 29 and 30 are bent upwardly from the side and end margins respectively of bottom 28. From the side margins of bottom 28 between tabs 32 and end arms 29, 30, laterally opposed retainer skirts 37 and retainer arms 38 are bent downwardly in embracing relation to the sides of low voltage relay control switch C. Skirts 37 and arms 38 include locking dogs 39 projecting longitudinally in a common direction for locking the main relay unit A, B to the low voltage relay control switch unit C, as described hereinafter.

The parts described above constitute the main relay frame and housing structure within which is mounted the switching mechanism of my aforesaid US, Pat. No. 3,428,924, identified herein for reference, as fixed contacts 41 and 42 (FIG. 5) mounted to bridge 25 and connected to conductors 43 and 44 extending through apertures in cover 17; a springblade shorting contact 45 mounted at one end on frame web 23, having a T-head on its opposite end disposed beneath and normally in open relation to contacts 41, 42; and a toothed rotary cam wheel 46 operable in a succession of steps to alternately raise the shorting contact 45 for closing against contacts 41, 42, and to release the contact 45 for spring-actuated self-opening movement. Cam wheel 46 has a lever arm 47 abutting one end thereof, a dog 48 on arm 47 being engageable with a tooth of the cam wheel to advance the wheel a distance equal to half the distance between adjacent teeth each time solenoid B is pulsed, and a hub 49 projecting loosely through arm 47 and encircled by a torsion spring 50 acting between frame wall 20 and the arm 47 to return the latter to its normal position indicated in phantom in FIG. 2, when solenoid B is deenergized.

Solenoid unit B comprises a coil 51 mounted in a cylindrical casing 52 secured to yoke bottom 28, and an armature 53 extending into frame 15 and carrying an actuator pin 54 overlying the projecting end of arm 37 and operable to swing the arm to an alternate position against the yielding opposition of spring 50 when the solenoid is pulsed.

The present invention provides a pair of coil 51 terminal contacts 55 (FIG. 8) on the exterior of casing 52 at its end adjacent yoke bottom 28, for engagement with contacts in low voltage relay control unit switch C, as described hereinafter.

Unit C comprises a rectangular casing block of insulating material (FIG. 8) having parallel sides snugly embraced by retainer skirts 37 and arms 38 of yoke 16, and having lateral lugs 61 beneath which the dogs 39 of these skirts and arms are engageable for locking the yoke 16 down against the block 60. In one end portion of block 60 (FIG. 8) is an elongated bottom opening 62 through which solenoid B is projected in assembling the unit A, B to the unit C. Opening 62 is of a length such as to allow relative movement between the main relay unit A, B, and the unit C between an initial assembly position in which solenoid B is adjacent the leftward end of opening 62 as viewed in FIG. 8 and the dogs 39 can be moved past the lugs 61, clearing them, for initial assembly (in which solenoid B is projected through the opening 62) and the final assembly position shown in FIG. 8, in which the yoke 15 has been slid longitudinally on block 60 to insert the dogs 39 beneath the lugs 61. For locking of the power unit A, B to unit C there is provided a locking lever 64 (FIG. 9) pivoted at 65 to yoke end arm 30 for pivotal movement from a position in unobstructing relation to the adjacent end of casing block 60, to the position shown in FIG. 9, wherein its tip overhangs the end of block 60, holding the dogs 39 in coupled engagement with lugs 61.

In a cavity in the other end of block 60 are three resilient contact blades 66, 67 and 68 (FIGS. 4 and 8) having respective shank portions mounted in spaced parallel relation at different levels on a stepped portion 69 of block 60 such as is shown in FIG. 11. The intermediate-height blade 66 is of 90 L-shape, having a contact end projecting between contacts of the upper blade 67 which is of 135 angular form, and on the lower blade 68 which is straight. Conductor leads 70. 71 and 72, attached to the three blades 67, 66, 68, may be extended through the adjacent end of bottom opening 62 for connection to external circuitry. On opposite sides of this end of opening 62 are a pair of terminals 73, 74 which are engaged by the solenoid coil contacts 55 when unit A, B is locked to the unit C.

The present invention adds to the main switch unit A, an actuator lever 76 of spring blade form anchored at one end beneath a boss 77 formed on web 23, projecting past the armature 53, engageable by a tooth of cam wheel 46, and having a movable end abutting the head of a push stud 78 of insulat ing material. The shank of stud 78 projects through an opening in yoke bottom 28 and engages an intermediate portion of contact blade 66 at the bend between its arms. Actuator lever 76 is spring loaded against cam wheel 46 so that its cam-follower projection 79 will drop into a space between cam teeth (e.g. in a position of cam wheel 46 one step beyond that shown in FIG. 2) and its moving end will then be retracted to release the stud 78 for return to a position in which it allows contact blade 66, by its inherent spring action, to assume a normal position closed against the opposed contact of upper blade 67. This will occur simultaneously with cam actuation of shorting contact 45 upwardly into closed engagement with fixed contacts 41 and. 42. On an ensuing actuation of cam wheel 46 (moving to the position shown in FIG. 2) the actuator lever 76 will be pressed downwardly, transmitting movement through stud 78 to intermediate low voltage contact blade 66 to reverse it from upper contact 67 to lower contact 68.

Casing block 60 is formed with apertured mounting cars 85 adapted to register with attachment holed adapted to receive self-tapping screws 86 of an electrical outlet box 87 for securing the assembly A, B, C, to the outlet box 87 with the high voltage relay unit A and low voltage relay control enclosed within the outlet box and the solenoid B projecting externally. (See FIG. 9).

Before proceeding with a description ofthe circuitry, it may be noted that the electrical parts of unit C are fully insulated from those of unit A though mechanically interconnected through insulator stud 78 for conjoint actuation. Also, the unit C functions as a mounting base for the entire assembly, providing for attachment to a standard outlet box with unit A completely enclosed therein.

FIG. 11 illustrates a modified form oflow voltage relay control switch unit C in which electrical connections from switch contacts 66, 67, and 68. to external circuitry are provided by terminal pins 170 attached to the respective contacts and projecting through the casing block 60, in lieu of the conductors 70-72 extending through opening 62 in FIG. 8.

Referring now to FIG. 12, there are shown therein a number of useful applications ofthe relay unit, as subcircuits in a composite circuit which could be utilized in its entirety under appropriate requirements, although it will be understood that the subcircuits also can be used independently or in any desired combination. A single low voltage power source (e.g. rectifier circuit 88) provides unfiltered half-wave rectified direct current low voltage (e.g. 24 volts) between the terminals of conductors 2 and 3: and lower voltage (e.g. 6 volts) alternating current for pilot light operation between the terminals of conductors 3 and 4. The relay units A, B and C, shown schematically, are connected to the four circuit conductors l, 2, 3 and 4 in various ways in circuits I, II, III, IV and V. Units A, B, and C are shown more fully in circuit l, (a master control circuit) and more abbreviated in circuits lIV inclusive. Conductors 43 and 44 of power switch unit A can be the service conductors of a conventional 120 volt circuit such as a building lighting circuit, controlled by service voltage switch unit A (contacts 41, 42, 45) which is actuated by solenoid unit B, receiving power from source 88. The essential components of units A, b and C are indicated in FIG. 12 by the same reference numerals as in FIGS. l-- 11.

Circuit I is a remote control system in which coil 5! of solenoid B is energized through low voltage relay control switch unit C by low voltage power delivered by conductors 2, 3 when a double throw remote control momentary switch 90 is actuated by shifting its movable contact (connected by a conductor 5 to terminal 74 of solenoid coil 51). Power in circuit 43, 44 is turned off when remote switch 90 is moved to its OFF" contact which is connected by conductor 6 to contact 67 of low voltage relay control switch unit C. With the intermediate contact 66 of switch unit C in its normal position closed on contact 67, current will flow from low voltage power conductor 3 through switch unit C to conductor 6, thence through conductor 5 to relay coil terminal 74, thence through the coil and from its terminal 73 to low voltage power conductor 2. Thus the momentary closing of switch 90 on conductor 6 will pulse the relay to reverse it, opening the power circuit across conductors 43, 44 and shifting the intermediate contact of the low voltage relay control switch unit C to its alternate contact 68, thus deenergizing the solenoid B. With the low voltage control switch unit C closed on its contact 68, a momentary closing of remote control switch 90 on its alternate on) contact, connected to relay contact 68 by a conductor 7, will again pulse the solenoid B by closing the circuit to coil terminal 74 through conductors 7 and 5. The ensuing step of cam wheel 46 will return the power switch A to its closed position and restore the low voltage control switch unit C to its position shown in FIG. 12, closed on its contact 67. A pilot light 91, connected across low voltage supply circuit 3, 4 through conductor 6 and the low voltage control switch contacts 66, 67, will light up during the time the low voltage control switch unit C is closed on its contact 67, thus indicating that the power switch A is closed to complete power circuit 43, 44.

Circuit ll illustrates a method of connecting additional relays to operate in synchronism with a master control relay system illustrated inCircuit l. V

The low voltage rectified, direct current from conductor 1 of the low voltage power supply is directed to an independent filter circuit R2, C2 across the rectified power supply lines 1 and 3. The filtered direct current stored voltage across the condenser C2 is discharge across the relay coil 51 when low voltage relay contacts 67, 66 are made and remote control conductors 6 and 5 are connected at 90. Circuit ll illustrates that the relays of Circuit l and Circuit II will operate in a synchronized sequence. Addition of other relays in a parallel circuit arrangement will cause the other relays thus connected in a Circuit ll configuration, to also operate in a synchronized sequence.

In Circuit III the remote control momentary contact switch 92 has only one make" contact that sequences the operation of the low voltage relay control switch unit C to alternately make or break the power control high voltage relay A, and the low voltage relay control switch contacts 67 and 66 are closed or opened. Contacts 67 and 66 provide a means of indicating through the pilot light 93 and alternating current from terminals 3 and 4 of the power supply 88 that the power relay A is closed.

Circuit lV, similar to Circuit Ill, provides a remote momentary contact switch 94 with one make contact that sequences the operation of the low voltage relay control switch unit C to make or break the power control high voltage relay A and the low voltage relay control switch contacts 67 and 66 are closed or opened. Contacts 67 and 66 provide a means for indicating, through the pilot light 95 and alternating current from terminals 3 and 4 of power supply 88, that the contacts of power relay A are made.

Circuit V, similar to Circuit ll illustrates a means for connecting two or more relays to operate in a synchronized sequence. As in Circuit II, a separate filter system R3, C3 is connected across the power supply 88 rectified direct current terminals 1 and 3. The low voltage power supply stored across C3 is discharged across solenoid coil 51 when low voltage relay control switch contacts 66 and 68 of relay in Circuit IV, are made and contacts 67 and 66 of switch unit C in circuit V are closed. The reverse operation takes place when contacts 66 and 67 of circuit IV are made and contacts 66 and 68 of the low voltage relay control switch unit in Circuit V are in a closed position. The power switches A of Circuits IV and V are thereby operated in synchronized sequence.

Additional circuits similar to Circuit V may be connected in parallel to synchronize more relays to operate with the master relay of Circuit l as illustrated in Circuit IV.

I claim:

1. In a remotely controllable relay assembly, in combination:

a high voltage switch unit including a housing having a bottom;

insulator means in said housing;

a normally open switch in said housing, including a fixed contact and an opposed flexible blade contact in opposed relation to said fixed contact;

a rotary cam in said housing, operable in successive steps of rotation to alternately move said blade to one position relative to said fixed contact and then to release said blade for self-return movement to an alternate position;

means including a pulse-operated solenoid for rotating said cam in said successive steps of rotation, one for each pulse-responsive movement of said solenoid;

a low voltage relay control switch unit including a casing attached externally to said bottom, and a relay control switch including a make and break contact and a flexible contact blade mounted in said casing;

and movement transmitting means including a part, engaging said cam on the side thereof opposite to said high voltage blade contact, projecting through said housing bottom into said casing, abutting said low voltage contact blade, and operable to move the same to one position of said relay control switch upon one step of said cam and to release said contact blade for self return to an alternate position upon the next step of said cam.

2. A relay assembly as defined in claim 1, wherein said movement transmitting means comprises:

a flexible actuator lever in said housing mounted at one end to said insulator means, extending past said cam on the side thereof opposite to said high voltage blade contact and yieldingly engaging in the same, said lever having a free end movable in response to successive steps of rotation of said cam;

and a push element slidably projecting through said housing bottom, one end thereof abutting said levers movable free end in said housing and its opposite end abutting said low voltage contact blade in said casing.

3. A relay as defined in claim 2, wherein said push element is in the form of a stud of insulating material extending through an opening in said housing bottom.

4. A relay as defined in claim 3, wherein said lever is arranged to be projected away from said cam when said high voltage switch contact blade is released for movement toward said cam and vice versa.

5. A relay as defined in claim 1, wherein said low voltage control switch is a double-throw relay actuated switch having alternate closed positions in which it is adapted to set up alternate circuits from a remote low voltage power source and remote momentary switch to said solenoid for successive pulsing thereof.

6. A relay assembly as defined in claim 1, wherein said low voltage relay control switch casing has means positioned for registration with attachment means of an electrical outlet box and for attachment thereto with said high voltage switch unit enclosed in said box and with said casing functioning as a divider between the power relay and said box.

7. A relay assembly as defined in claim 1, wherein said low voltage relay control switch casing comprises a rectangular block of insulating material havin inte ral apertured ears projecting from opposite sides of sai block in positions for registration with attachment tabs of an electrical outlet box and for attachment thereto with said high voltage switch unit enclosed in said box.

8. A relay assembly as defined in claim 1, wherein said low voltage relay control switch casing comprises a block ofins'ulating material having therein an elongated opening through which said solenoid projects from the bottom of said high voltage switch housing;

said housing and casing including interengageable means adapted to lock said casing to said housing in an assembly operation in which said solenoid is first extended through said opening adjacent one end thereof and is then shifted laterally in said opening to a position adjacent the other end thereof, thus effecting relative shifting of said housing and casing to lock them together.

9. A relay assembly as defined in claim 8, wherein said lock means comprises retainer parts projecting from respective sides of said housing in embracing relation to the sides of said casing, and dogs projecting from the ends of said retainer parts longitudinally of said casing and adapted to hook beneath lugs projecting laterally from the side of said casing.

10. A relay assembly as defined in claim 9, including a pivotal latch on an end of said housing movable to a position obstructing return movement of said casing relative to said housing from the locked position.

11. A relay assembly as defined in claim 1, including a generally rectangular frame of insulating material having an open bottom, mounted in said housing;

said housing being in the form of a yoke embodying end arms abutting the ends of said frame and having lateral retainer lips embracing the four corners of said frame, said housing bottom closing said open bottom of the frame;

and a cover of flat plate form closing the top of said housing yoke and retaining said frame therein.

12. A relay assembly as defined in claim 11,

said housing yoke including lateral tabs extending from said bottom to said cover and having at their ends bendable tabs adapted to project over and engage the central portion of said cover for securing it to the housing yoke;

said retainer lips having, adjacent their upper ends, notches in which the four corners of said cover are received, for securing them to said housing yoke. 

1. In a remotely controllable relay assembly, in combination: a high voltage switch unit including a housing having a bottom; insulator means in said housing; a normally open switch in said housing, including a fixed contact and an opposed flexible blade contact in opposed relation to said fixed contact; a rotary cam in said housing, operable in successive steps of rotation to alternately move said blade to one position relative to said fixed contact and then to release said blade for self-return movement to an alternate position; means including a pulse-operated solenoid for rotating said cam in said successive steps of rotation, one for each pulseresponsive movement of said solenoid; a low voltage relay control switch unit including a casing attached externally to said bottom, and a relay control switch including a make and break contact and a flexible contact blade mounted in said casing; and movement transmitting means including a part, engaging said cam on the side thereof opposite to said high voltage blade contact, projecting through said housing bottom into said casing, abutting said low voltage contact blade, and operable to move the same to one position of said Relay control switch upon one step of said cam and to release said contact blade for self return to an alternate position upon the next step of said cam.
 2. A relay assembly as defined in claim 1, wherein said movement transmitting means comprises: a flexible actuator lever in said housing mounted at one end to said insulator means, extending past said cam on the side thereof opposite to said high voltage blade contact and yieldingly engaging in the same, said lever having a free end movable in response to successive steps of rotation of said cam; and a push element slidably projecting through said housing bottom, one end thereof abutting said lever''s movable free end in said housing and its opposite end abutting said low voltage contact blade in said casing.
 3. A relay as defined in claim 2, wherein said push element is in the form of a stud of insulating material extending through an opening in said housing bottom.
 4. A relay as defined in claim 3, wherein said lever is arranged to be projected away from said cam when said high voltage switch contact blade is released for movement toward said cam and vice versa.
 5. A relay as defined in claim 1, wherein said low voltage control switch is a double-throw relay actuated switch having alternate closed positions in which it is adapted to set up alternate circuits from a remote low voltage power source and remote momentary switch to said solenoid for successive pulsing thereof.
 6. A relay assembly as defined in claim 1, wherein said low voltage relay control switch casing has means positioned for registration with attachment means of an electrical outlet box and for attachment thereto with said high voltage switch unit enclosed in said box and with said casing functioning as a divider between the power relay and said box.
 7. A relay assembly as defined in claim 1, wherein said low voltage relay control switch casing comprises a rectangular block of insulating material having integral apertured ears projecting from opposite sides of said block in positions for registration with attachment tabs of an electrical outlet box and for attachment thereto with said high voltage switch unit enclosed in said box.
 8. A relay assembly as defined in claim 1, wherein said low voltage relay control switch casing comprises a block of insulating material having therein an elongated opening through which said solenoid projects from the bottom of said high voltage switch housing; said housing and casing including interengageable means adapted to lock said casing to said housing in an assembly operation in which said solenoid is first extended through said opening adjacent one end thereof and is then shifted laterally in said opening to a position adjacent the other end thereof, thus effecting relative shifting of said housing and casing to lock them together.
 9. A relay assembly as defined in claim 8, wherein said lock means comprises retainer parts projecting from respective sides of said housing in embracing relation to the sides of said casing, and dogs projecting from the ends of said retainer parts longitudinally of said casing and adapted to hook beneath lugs projecting laterally from the side of said casing.
 10. A relay assembly as defined in claim 9, including a pivotal latch on an end of said housing movable to a position obstructing return movement of said casing relative to said housing from the locked position.
 11. A relay assembly as defined in claim 1, including a generally rectangular frame of insulating material having an open bottom, mounted in said housing; said housing being in the form of a yoke embodying end arms abutting the ends of said frame and having lateral retainer lips embracing the four corners of said frame, said housing bottom closing said open bottom of the frame; and a cover of flat plate form closing the top of said housing yoke and retaining said frame therein.
 12. A relay assembly as defined in claim 11, said housing yoke including lateral tabS extending from said bottom to said cover and having at their ends bendable tabs adapted to project over and engage the central portion of said cover for securing it to the housing yoke; said retainer lips having, adjacent their upper ends, notches in which the four corners of said cover are received, for securing them to said housing yoke. 